| Little amp [message #31106] |
Tue, 24 May 2005 18:28  |
PakProtector
Messages: 935
Registered: May 2009
|
Illuminati (2nd Degree) |
|
|
|
Here is a neat little one: E-Linear 6V6's. Iron:
Dynaco Z565 or modern copies for the OPTx
Dynaco St.70 power Iron, probably best to get a modern improved version.
One 10Hy power inductor for the L-C power supply. 500 mA unit from Hammond will be adequate. Cascode 6BQ7 or 6BK7B for a diff amp cascode front like Merlin
100 uF/370vac cap like spec-ed for Guinevere for the PS cap. It will probably be good for ~12 W or so. Probably just out of Class A bias, but that's OK. B+ will be ~300. If somebody wants to build this, I'll loan a pair of the Z565's. Email me.
regards,
Douglas Praise the Lord, and pass the 813's!
|
|
|
|
|
|
|
|
| Re: Little amp [message #31109 is a reply to message #31108] |
Wed, 25 May 2005 04:39  |
PakProtector
Messages: 935
Registered: May 2009
|
Illuminati (2nd Degree) |
|
|
|
The schematic will look a lot like( nearly the same as ) Merlin, but with some component value adjustments. Probably require a 2 sq foot top plate to do comfortably and w/o crowding. The front end is the big trouble with that design, it requires two CCS per channel. They are not too difficult. one uses the TO92 cased LND150 and can be built on ~2 cm^2 with two resistors and two mosfets.
regards,
Douglas
|
|
|
|
| Re: Little amp [message #31110 is a reply to message #31107] |
Wed, 25 May 2005 04:44 |
PakProtector
Messages: 935
Registered: May 2009
|
Illuminati (2nd Degree) |
|
|
|
The schematic is very similar to Merlin. No grid choke required. I should probably re-draw and mail the paper to Wayne for digitizig and posting. You might want to hold off with the Guinevere rebuild as 12B4 amplifier valves are a worthy experiment requiring a second socket and a bit of re-wire only. Yes I'd support any and all questions on the 6V6 amp build.
regards,
Douglas
|
|
|
|
|
|
| Re: Little amp [message #31112 is a reply to message #31111] |
Wed, 25 May 2005 14:26 |
PakProtector
Messages: 935
Registered: May 2009
|
Illuminati (2nd Degree) |
|
|
|
well...the CCS are all self bias, as this is a characteristic of the depletion mode MOSFETS. Their drift performance has not caused me any troubles as of yet. Smaller is easier, save for the complexity of the special E-Linear cascode Circuit I feel is the best approach to this particular design. I think I rather moderate voltage pentodes to triodes. Not much sport involved with triode finals in many of the aspects I find interesting. I am still going to do the 4E27 amp. Soon enough I'll be paid enough to afford it. I am not 'UP' on chassis construction companies. I am going to buy a drillpress for my shop...
regards,
Douglas
|
|
|
|
|
|
| right where it belongs... [message #31114 is a reply to message #31113] |
Wed, 25 May 2005 16:50 |
PakProtector
Messages: 935
Registered: May 2009
|
Illuminati (2nd Degree) |
|
|
|
THe 6V6 option offers a lighter PS option. ~35 mA/valve of idle current. With 6-10 mA allowed for the front end, we'd be looking at consuming ~160 mA of 300VDC. No big deal for the St.70 power Iron. It is just an option in case the DH stuff was looking a bit complex( and it is a bit more compared to IDH valves like the 6V6 ). The 6V6 also has a fairly light heater load.
regards,
Douglas
|
|
|
|
|
|
Posting Rules
Members
Search
Help
Register
Login
Get a T-Shirt!
